The term Portable data terminal (PDT) refers to data collection devices used to collect, process, and transfer data to a larger data processing system. Most PDTs are ruggedized to some extent for use in industrial environments. The tougher the environment, the more robust the PDT. PDT's are available from several sources, including the assignee of the present application: HAND HELD PRODUCTS, INC.
A PDT generally comprises a mobile computer, a keypad, and a data acquisition device. The mobile computer generally comprises a hand held (or “pocket”) computing device, such as those available from INTEL, PALM, HEWLETT PACKARD, and DELL. Keypads come in a variety of alpha-numeric and numeric configurations. The data acquisition device generally comprises a device that captures data from, for example, radio frequency IDs (RFID), images, and bar codes. Data may also be captured via keypad entry and utilization of a touch pad associated with the mobile computer.
FIG. 1A is an orthogonal view of a known PDT 100. FIG. 1B is a plan view of the known PDT 100. The illustrated example utilizes a popular form factor incorporating a body 102 and a handle 101. The body 102 generally supports a variety of components, including: a battery (not shown but typically located on the rear half of the body): an LCD with touch screen 106; a keyboard 108 (including a scan button 108a): a scan engine 110: and a data/charging port 112 (not fully illustrated). The scan engine 110 may comprise, for example, an image engine or a laser engine. The data/charging port 112 typically comprises a proprietary interface with one set of pins or pads for the transmitting and receiving of data and a second set of pins or pads for receiving power for powering the system and/or charging the battery.
The handle 101, extending from a bottom surface of the body 102, incorporates a trigger 114. In use, the user may actuate either tile scan key 108a or the trigger 114 to initiate a frame capture via the image engine 110. The captured frame may either be processed as an image or as a data carrier. In the first case, the captured frame may undergo some post capture image processing, such as de-speckling or sharpening and then stored as an image file (e.g. a bitmap, jpeg of gif file) and possibly displayed. In the second case the captured frame also undergoes some post capture image processing but the image is then analyzed, e.g. decoded, to identify data represented therein. The decoded data is stored and possibly displayed on the PDT 100. Additional processing of the image or data may take place on the PDT 100 and/or a data processing resource to which the data is transmitted via any available transport mechanism on the PDT 100. Some examples of known transport mechanisms utilized by PDT's include: Bluetooth, WiFi, GSM, GPRS, CDMA, USB, IEEE 1394, IrDA, removable FLASH memory, parallel and serial ports (including for example, RS-232).
A recent development in the PDT marketplace is the integration of location determination hardware and software, such as the Global Positioning System (GPS) and Galileo system. Using GPS as an example, the system generally comprises a GPS receiver that receives a signal from one or more GPS satellites and calculates a location of the receiver from the received signal(s). To calculate a location, the GPS receiver demodulates the signal(s) from the GPS satellite and acquires orbit data for the GPS satellite. Then, from an orbit of the GPS satellite, current time information, and a delay time of a received signal, the GPS receiver derives a three-dimensional location by solving a series of simultaneous equations.
One application for which the combination of a GPS receiver and a PDT is useful is package delivery. The combination of a PDT and GPS receiver allows a delivery driver to stamp delivery data with location data. One potential problem is that GPS systems are line of sight systems that require a direct line of sight to the sky. Such a line of sight may be difficult to obtain with a portable device that is often used in the back of a delivery truck or within entryways and buildings to which the driver is delivering packages. Another potential problem is managing the power drain and incorporating yet another receiver and antenna in the already crowded housing of a PDT.
Accordingly, the present Inventors have recognized a need for apparatus and methods to provide GPS data to a PDT without limiting the functionality of either the GPS unit or the PDT.